The opening of Brazil's $13 billion Belo Monte dam in the Amazon could be delayed if a court order requiring construction to stop is not overturned by December, the head of the consortium building the project said on Friday.

A regional judge called for an immediate halt to construction on Tuesday after years of high-profile criticism. The likes of Hollywood director James Cameron and the Inter-American Court on Human Rights have said Belo Monte would displace indigenous people in the Amazon rain forest.

President Dilma Rousseff, however, has said such mega dams are needed to meet the energy demands of Brazil's growing consumer class -- the result of intense poverty alleviation in Latin America's largest economy.

"This situation must be resolved very quickly in order to take advantage of a hydrological window," President of Norte Energia (Northern Energy) Duilio Figueiredo told Reuters, referring the seasonal rains in the region.

He pointed to a dry period that ends in early December in the Amazon state of Para, where the consortium is building what would be the world's third largest dam on the Xingu River, an Amazon River tributary.

Figueiredo said he was confident the court decision would be overturned. Norte Energia has not yet pushed back Belo Monte's official 2015 start date despite strikes from construction workers and protests from indigenous tribes in past months.

Minas Gerais state energy company Cemig, part of the Norte Energia consortium that also includes state-run Eletrobras, said on Thursday that 11 percent of work on Belo Monte is complete.

The consortium also received a draft communique from Brazil's state development bank BNDES detailing long-term financing essential for the project, Figueiredo said.

"We expect the funding to come through by November, the amount is in line with what we imagined, between 19 and 20 billion reais ($9.4-$9.9 billion)," he told Reuters.

Brazil's Regional Federal Tribunal argued that Brazil did not consult affected tribes before approving the project as required by Brazil's constitution and U.N. Treaty 169 on indigenous rights.

Country's including Peru, Bolivia, Brazil and Ecuador have sparred with indigenous groups as Latin America struggles to reconcile economic development in the Amazon while preserving traditional lifestyles of indigenous peoples.